<?php
/**
 * CNumberFormatter class file.
 *
 * @author Wei Zhuo <weizhuo[at]gmail[dot]com>
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CNumberFormatter provides number localization functionalities.
 *
 * CNumberFormatter formats a number (integer or float) and outputs a string
 * based on the specified format. A CNumberFormatter instance is associated with a locale,
 * and thus generates the string representation of the number in a locale-dependent fashion.
 *
 * CNumberFormatter currently supports currency format, percentage format, decimal format,
 * and custom format. The first three formats are specified in the locale data, while the custom
 * format allows you to enter an arbitrary format string.
 *
 * A format string may consist of the following special characters:
 * <ul>
 * <li>dot (.): the decimal point. It will be replaced with the localized decimal point.</li>
 * <li>comma (,): the grouping separator. It will be replaced with the localized grouping separator.</li>
 * <li>zero (0): required digit. This specifies the places where a digit must appear (will pad 0 if not).</li>
 * <li>hash (#): optional digit. This is mainly used to specify the location of decimal point and grouping separators.</li>
 * <li>currency (¤): the currency placeholder. It will be replaced with the localized currency symbol.</li>
 * <li>percentage (%): the percetage mark. If appearing, the number will be multiplied by 100 before being formatted.</li>
 * <li>permillage (‰): the permillage mark. If appearing, the number will be multiplied by 1000 before being formatted.</li>
 * <li>semicolon (;): the character separating positive and negative number sub-patterns.</li>
 * </ul>
 *
 * Anything surrounding the pattern (or sub-patterns) will be kept.
 *
 * The followings are some examples:
 * <pre>
 * Pattern "#,##0.00" will format 12345.678 as "12,345.68".
 * Pattern "#,#,#0.00" will format 12345.6 as "1,2,3,45.60".
 * </pre>
 * Note, in the first example, the number is rounded first before applying the formatting.
 * And in the second example, the pattern specifies two grouping sizes.
 *
 * CNumberFormatter attempts to implement number formatting according to
 * the {@link http://www.unicode.org/reports/tr35/ Unicode Technical Standard #35}.
 * The following features are NOT implemented:
 * <ul>
 * <li>significant digit</li>
 * <li>scientific format</li>
 * <li>arbitrary literal characters</li>
 * <li>arbitrary padding</li>
 * </ul>
 *
 * @author Wei Zhuo <weizhuo[at]gmail[dot]com>
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CNumberFormatter.php 2798 2011-01-01 19:29:03Z qiang.xue $
 * @package system.i18n
 * @since 1.0
 */
class CNumberFormatter extends CComponent
{
    private $_locale;
    private $_formats=array();

    /**
     * Constructor.
     * @param mixed $locale locale ID (string) or CLocale instance
     */
    public function __construct($locale)
    {
        if(is_string($locale))
        $this->_locale=CLocale::getInstance($locale);
        else
        $this->_locale=$locale;
    }

    /**
     * Formats a number based on the specified pattern.
     * Note, if the format contains '%', the number will be multiplied by 100 first.
     * If the format contains '‰', the number will be multiplied by 1000.
     * If the format contains currency placeholder, it will be replaced by
     * the specified localized currency symbol.
     * @param string $pattern format pattern
     * @param mixed $value the number to be formatted
     * @param string $currency 3-letter ISO 4217 code. For example, the code "USD" represents the US Dollar and "EUR" represents the Euro currency.
     * The currency placeholder in the pattern will be replaced with the currency symbol.
     * If null, no replacement will be done.
     * @return string the formatting result.
     */
    public function format($pattern,$value,$currency=null)
    {
        $format=$this->parseFormat($pattern);
        $result=$this->formatNumber($format,$value);
        if($currency===null)
        return $result;
        else if(($symbol=$this->_locale->getCurrencySymbol($currency))===null)
        $symbol=$currency;
        return str_replace('¤',$symbol,$result);
    }

    /**
     * Formats a number using the currency format defined in the locale.
     * @param mixed $value the number to be formatted
     * @param string $currency 3-letter ISO 4217 code. For example, the code "USD" represents the US Dollar and "EUR" represents the Euro currency.
     * The currency placeholder in the pattern will be replaced with the currency symbol.
     * @return string the formatting result.
     */
    public function formatCurrency($value,$currency)
    {
        return $this->format($this->_locale->getCurrencyFormat(),$value,$currency);
    }

    /**
     * Formats a number using the percentage format defined in the locale.
     * Note, if the percentage format contains '%', the number will be multiplied by 100 first.
     * If the percentage format contains '‰', the number will be multiplied by 1000.
     * @param mixed $value the number to be formatted
     * @return string the formatting result.
     */
    public function formatPercentage($value)
    {
        return $this->format($this->_locale->getPercentFormat(),$value);
    }

    /**
     * Formats a number using the decimal format defined in the locale.
     * @param mixed $value the number to be formatted
     * @return string the formatting result.
     */
    public function formatDecimal($value)
    {
        return $this->format($this->_locale->getDecimalFormat(),$value);
    }

    /**
     * Formats a number based on a format.
     * This is the method that does actual number formatting.
     * @param array $format format with the following structure:
     * <pre>
     * array(
     * 	'decimalDigits'=>2,     // number of required digits after decimal point; 0s will be padded if not enough digits; if -1, it means we should drop decimal point
     *  'maxDecimalDigits'=>3,  // maximum number of digits after decimal point. Additional digits will be truncated.
     * 	'integerDigits'=>1,     // number of required digits before decimal point; 0s will be padded if not enough digits
     * 	'groupSize1'=>3,        // the primary grouping size; if 0, it means no grouping
     * 	'groupSize2'=>0,        // the secondary grouping size; if 0, it means no secondary grouping
     * 	'positivePrefix'=>'+',  // prefix to positive number
     * 	'positiveSuffix'=>'',   // suffix to positive number
     * 	'negativePrefix'=>'(',  // prefix to negative number
     * 	'negativeSuffix'=>')',  // suffix to negative number
     * 	'multiplier'=>1,        // 100 for percent, 1000 for per mille
     * );
     * </pre>
     * @param mixed $value the number to be formatted
     * @return string the formatted result
     */
    protected function formatNumber($format,$value)
    {
        $negative=$value<0;
        $value=abs($value*$format['multiplier']);
        if($format['maxDecimalDigits']>=0)
        $value=round($value,$format['maxDecimalDigits']);
        $value="$value";
        if(($pos=strpos($value,'.'))!==false)
        {
            $integer=substr($value,0,$pos);
            $decimal=substr($value,$pos+1);
        }
        else
        {
            $integer=$value;
            $decimal='';
        }

        if($format['decimalDigits']>strlen($decimal))
        $decimal=str_pad($decimal,$format['decimalDigits'],'0');
        if(strlen($decimal)>0)
        $decimal=$this->_locale->getNumberSymbol('decimal').$decimal;

        $integer=str_pad($integer,$format['integerDigits'],'0',STR_PAD_LEFT);
        if($format['groupSize1']>0 && strlen($integer)>$format['groupSize1'])
        {
            $str1=substr($integer,0,-$format['groupSize1']);
            $str2=substr($integer,-$format['groupSize1']);
            $size=$format['groupSize2']>0?$format['groupSize2']:$format['groupSize1'];
            $str1=str_pad($str1,(int)((strlen($str1)+$size-1)/$size)*$size,' ',STR_PAD_LEFT);
            $integer=ltrim(implode($this->_locale->getNumberSymbol('group'),str_split($str1,$size))).$this->_locale->getNumberSymbol('group').$str2;
        }

        if($negative)
        $number=$format['negativePrefix'].$integer.$decimal.$format['negativeSuffix'];
        else
        $number=$format['positivePrefix'].$integer.$decimal.$format['positiveSuffix'];

        return strtr($number,array('%'=>$this->_locale->getNumberSymbol('percentSign'),'‰'=>$this->_locale->getNumberSymbol('perMille')));
    }

    /**
     * Parses a given string pattern.
     * @param string $pattern the pattern to be parsed
     * @return array the parsed pattern
     * @see formatNumber
     */
    protected function parseFormat($pattern)
    {
        if(isset($this->_formats[$pattern]))
        return $this->_formats[$pattern];

        $format=array();

        // find out prefix and suffix for positive and negative patterns
        $patterns=explode(';',$pattern);
        $format['positivePrefix']=$format['positiveSuffix']=$format['negativePrefix']=$format['negativeSuffix']='';
        if(preg_match('/^(.*?)[#,\.0]+(.*?)$/',$patterns[0],$matches))
        {
            $format['positivePrefix']=$matches[1];
            $format['positiveSuffix']=$matches[2];
        }

        if(isset($patterns[1]) && preg_match('/^(.*?)[#,\.0]+(.*?)$/',$patterns[1],$matches))  // with a negative pattern
        {
            $format['negativePrefix']=$matches[1];
            $format['negativeSuffix']=$matches[2];
        }
        else
        {
            $format['negativePrefix']=$this->_locale->getNumberSymbol('minusSign').$format['positivePrefix'];
            $format['negativeSuffix']=$format['positiveSuffix'];
        }
        $pat=$patterns[0];

        // find out multiplier
        if(strpos($pat,'%')!==false)
        $format['multiplier']=100;
        else if(strpos($pat,'‰')!==false)
        $format['multiplier']=1000;
        else
        $format['multiplier']=1;

        // find out things about decimal part
        if(($pos=strpos($pat,'.'))!==false)
        {
            if(($pos2=strrpos($pat,'0'))>$pos)
            $format['decimalDigits']=$pos2-$pos;
            else
            $format['decimalDigits']=0;
            if(($pos3=strrpos($pat,'#'))>=$pos2)
            $format['maxDecimalDigits']=$pos3-$pos;
            else
            $format['maxDecimalDigits']=$format['decimalDigits'];
            $pat=substr($pat,0,$pos);
        }
        else   // no decimal part
        {
            $format['decimalDigits']=0;
            $format['maxDecimalDigits']=0;
        }

        // find out things about integer part
        $p=str_replace(',','',$pat);
        if(($pos=strpos($p,'0'))!==false)
        $format['integerDigits']=strrpos($p,'0')-$pos+1;
        else
        $format['integerDigits']=0;
        // find out group sizes. some patterns may have two different group sizes
        $p=str_replace('#','0',$pat);
        if(($pos=strrpos($pat,','))!==false)
        {
            $format['groupSize1']=strrpos($p,'0')-$pos;
            if(($pos2=strrpos(substr($p,0,$pos),','))!==false)
            $format['groupSize2']=$pos-$pos2-1;
            else
            $format['groupSize2']=0;
        }
        else
        $format['groupSize1']=$format['groupSize2']=0;

        return $this->_formats[$pattern]=$format;
    }
}